Robot

ABSTRACT

A robot includes a gripping section adapted to grip an object by open and close a pair of finger sections, a moving device adapted to relatively move the object and the gripping section, and a control device adapted to control the moving device to move the gripping section relatively toward the object, and dispose the pair of finger sections in a periphery of the object, and then control the gripping section to open and close the pair of finger sections in a plane parallel to a mounting surface on which the object is mounted, pinch the object between the pair of finger sections from a lateral side of the object, and grip the object with the gripping section at least three contact points.

BACKGROUND

1. Technical Field

The present invention relates to a robot.

2. Related Art

In the past, vertical articulated robots, horizontal articulated robots(scalar robots), Cartesian coordinate robots, and so on have beendeveloped as industrial robots, and are selected in accordance withpurposes suitable for the features thereof. In such robots, a grippingsection for gripping the object is moved to a target position, and thenthe gripping section is made to grip the object.

Such industrial robots are required to effectively grab the object,which takes a variety of unspecified postures, in a predeterminedposture in working processes such as an automatic assembly process. Forexample, in the robot described in JP-A-2009-78312 (Document 1), it isarranged that a chuck mechanism for gripping the object can be rotatedby a rotation mechanism in forward and reverse directions around thecenter shaft for supporting the chuck itself, and further, the rotationmechanism itself can pivot within a predetermined downward angle rangewith a pivot mechanism.

According to the technology of Document 1, since the control devicecontrols the rotation mechanism and the pivot mechanism, it isconceivable that the chuck can be oriented toward a variety ofdirections, and the object in a variety of postures can be gripped withthe chuck mechanism due to the control of the control device.

However, if the object is, for example, small-sized and lightweight, itbecomes difficult to accurately detect the position and the posture ofthe object using a camera, and accurate positioning of the chuckmechanism for gripping the object is not achievable in some cases. Ifthe accurate positioning of the chuck mechanism is not achievable, theobject and the chuck mechanism might have contact with each other at anunintended place during the gripping operation. On that occasion, sincethe object is lightweight, the object moves in an unintended direction,and there arises a problem that it is not achievable to hold the objectat a desired position or a problem that the object flies out of thegripping space.

SUMMARY

An advantage of some aspects of the invention is to provide a robotcapable of reliably gripping the object at a predetermined positionwithout failing to catch the object.

An aspect of the invention is directed to a robot including a grippingsection adapted to grip an object by open and close a pair of fingersections, a moving device adapted to relatively move the object and thegripping section, and a control device adapted to control the movingdevice to move the gripping section relatively toward the object, anddispose the pair of finger sections in a periphery of the object, andthen control the gripping section to open and close the pair of fingersections in a plane parallel to a mounting surface on which the objectis mounted, pinch the object between the pair of finger sections from alateral side of the object, and grip the object with the grippingsection at least three contact points.

According to the robot described above, since the pair of fingersections are moved to the periphery of the object and then opened andclosed in the plane parallel to the mounting surface on which the objectis mounted due to the control by the control device, it results that theperiphery of the object is surrounded by the pair of finger sections.Thus, the object is prevented from jumping out of the area surrounded bythe pair of finger sections. Further, since the pair of finger sectionspinch the object from the lateral side thereof, the object moves withthe operation of the pair of finger sections, and thus the position isadjusted. Further, since the gripping section grips the object at leastthree contact points, it is possible to restrict the position of theobject and to grip the object stably with the friction at the contactpoints. According to such an operation of the gripping section asdescribed above, the object can be gripped at a predetermined position.Therefore, it is possible to provide the robot capable of preventing theobject from escaping, and reliably gripping the object at apredetermined position.

The robot of the aspect of the invention may be configured such that thegripping section opens and closes the pair of finger sections bytranslating the pair of finger sections in a direction of getting awayfrom each other and a direction of getting close to each other.

According to the robot of this configuration, it is arranged that thepair of finger sections are translated to each other to thereby pinchthe object from the lateral side thereof. Therefore, it results that theobject moves in roughly the same direction as the open/close directionof the pair of finger sections. Therefore, it is possible to make theopen/close mechanism of the pair of finger sections have an easy andsimple configuration.

The robot of the aspect of the invention may be configured such that thegripping section opens and closes the pair of finger sections byrotating at least one of the pair of finger sections around a rotationalaxis perpendicular to the mounting surface.

According to the robot of this configuration, it is arranged that atleast one of the pair of finger sections rotates to thereby pinch theobject from the lateral side thereof. Therefore, it results that theobject moves so as to be pulled in in the direction of the rotation ofthe at least one of the pair of finger sections. Therefore, it ispossible to make the open/close mechanism of the pair of finger sectionshave an easy and simple configuration.

The robot of the aspect of the invention may be configured such that atleast one of the pair of finger sections has contact with the object atleast two contact points on a gripping surface adapted to grip theobject from the lateral side.

By thus increasing the contact points, it becomes easy to grip theobject stably at a predetermined position.

The robot of the aspect of the invention may be configured such that thegripping section is provided with a main body section to which the pairof finger sections are coupled, and grips the object at least threecontact points by making the object have contact with the pair of fingersections and the main body section.

The robot of the aspect of the invention may be configured such that atleast one of the pair of finger sections has a guard adapted to preventthe object from jumping out in a direction perpendicular to the mountingsurface, the guard being disposed on an opposite side to the mountingsurface across the object.

According to the robot of this configuration, it is possible to preventthe object from jumping out upward when pinching the object.

The robot of the aspect of the invention may be configured such that acamera adapted to take a picture of the object is further provided, andthe control device detects a position of the object based on a result oftaking a picture by the camera, and then controls the moving device tomove the gripping section relatively toward the object.

According to the robot of this configuration, the accurate positioningof the gripping section for gripping the object can be performed.

The robot of the aspect of the invention may be configured such that thegripping section is provided with a main body section to which the pairof finger sections are coupled, and the camera is attached to the mainbody section.

According to the robot of this configuration, since the camera isdisposed at a position near to the pair of finger sections, it ispossible to perform accurate positioning of the pair of finger sectionsfor gripping the object.

The robot of the aspect of the invention may be configured such thateach of the pair of finger sections includes a tip section disposed inparallel to the mounting surface, and adapted to grip the object, andabase end section disposed in a direction of getting apart from themounting surface, and coupled to the main body section.

In the case of gripping the object mounted on the mounting surface, bymaking the pair of finger sections have contact with the mountingsurface while making the pair of finger sections perform the grippingoperation, it becomes easy to stably grip the object. If there isadopted the configuration, for example, in which the tip section and thebase end section are arranged in parallel to each other in the pair offinger sections, the main body section and the mounting surface havecontact with each other when gripping the object, and the tip sectionand the mounting surface become distant from each other to thereby makeit difficult to stably grip the object. However, according to theconfiguration, it becomes easy to make the tip sections of the pair offinger sections have contact with the mounting surface. Therefore, itbecomes easy to grip the object stably at a predetermined position.

The robot of the aspect of the invention may be configured such that thetip section of each of the pair of finger sections has a flat surfaceopposed to the mounting surface.

According to the robot of this configuration, it becomes easy to makethe tip sections of the pair of finger sections have contact with themounting surface compared to the configuration in which the surface ofthe tip section of each of the pair of finger sections opposed to themounting surface is an uneven surface. Therefore, it becomes easy togrip the object stably at a predetermined position.

The robot of the aspect of the invention may be configured such that thetip section and the base end section are arranged so as to eliminate anoverlap between the tip section and the base end section in a view froma direction in which the camera takes a picture of the tip section.

According to the robot of this configuration, it is possible to performthe gripping operation while checking the gripping operation of the tipsections.

The robot of the aspect of the invention may be configured such that theangle formed between the tip section and the base end section is anobtuse angle.

If there is adopted a configuration, for example, in which the angleformed between the tip section and the base end section is an acuteangle, there is a possibility that the tip section is shaded by the baseend section when viewed from the direction in which the image of the tipsection is taken by the camera, and it becomes difficult to detect theaccurate gripping operation of the tip sections. However, according tothe configuration, the tip sections are hardly shaded by the base endsections viewed from the direction in which the image of the tipsections is taken by the camera. Therefore, it becomes easy to performthe gripping operation while checking the gripping operation of the tipsections.

The robot of the aspect of the invention may be configured such that thegripping section includes a detection device adapted to detect a forcefor gripping the object, and the control device controls the force ofthe gripping section for gripping the object based on a detection resultof the detection device.

According to the robot of this configuration, the gripping force of thegripping section can be controlled so as not to apply an excessive loadto the object. Therefore, it becomes possible to prevent the object frombeing deformed or damaged when gripping the object.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a perspective view showing a schematic configuration of arobot according to a first embodiment of the invention.

FIG. 2 is a plan view showing a configuration of a gripping sectionaccording to the first embodiment.

FIGS. 3A through 3D are plan views showing an operation of the grippingsection according to the first embodiment.

FIG. 4 is a flowchart showing an operation of the robot according to thefirst embodiment.

FIG. 5 is a plan view showing a configuration of a gripping sectionaccording to a second embodiment.

FIGS. 6A through 6D are plan views showing an operation of the grippingsection according to the second embodiment.

FIGS. 7A and 7B are diagrams showing a configuration of a grippingsection according to a third embodiment.

FIGS. 8A and 8B are diagrams showing a condition of the gripping sectionaccording to the third embodiment gripping the object.

FIGS. 9A and 9B are diagrams showing a configuration of a grippingsection according to a fourth embodiment.

FIG. 10 is a plan view showing a configuration of a gripping sectionaccording to a fifth embodiment.

FIGS. 11A through 11D are plan views showing an operation of thegripping section according to the fifth embodiment.

FIGS. 12A through 12C are plan views respectively showing first throughthird modified examples of the gripping section.

FIGS. 13A through 13F are plan views respectively showing fourth throughninth modified examples of the gripping section.

FIG. 14 is a plan view showing a tenth modified example of the grippingsection.

FIGS. 15A through 15C are side views respectively showing elevenththrough thirteenth modified examples of the gripping section.

FIG. 16 is a diagram showing a relationship between the forces causedwhen gripping the object with the gripping section.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, some embodiments of the invention will be described withreference to the accompanying drawings. The embodiments each show anaspect of the invention, but do not limit the scope of the invention,and can arbitrarily be modified within a technical concept of theinvention. Further, in the drawings explained hereinafter, in order formaking each constituent easy to understand, the actual structures andthe structures of the drawings are different from each other in scalesize, number, and so on.

In the explanation described below, the XYZ Cartesian coordinate systemshown in FIG. 1 is set, and each of the members will be explained withreference to the Cartesian coordinate system. In the Cartesiancoordinate system, the X axis and the Y axis are set in parallel to ahorizontal plane and perpendicular to each other, and the Z axis is setin a direction (a vertical direction) perpendicular to both of the Xaxis and the Y axis.

First Embodiment

FIG. 1 is a perspective view showing a schematic configuration of arobot 1 according to a first embodiment of the invention. In FIG. 1, thereference symbol W1 denotes a first object and the reference symbol W2denotes a second object. Further, the reference symbol L1A denotes arotational axis of a first arm 21A, the reference symbol L2A denotes arotational axis of a second arm 22A, the reference symbol L3A denotes arotational axis of a third arm 23A, and the reference symbol L4A denotesa rotational axis of a gripping section 10A. The reference symbol L1Bdenotes a rotational axis of a first arm 21B, the reference symbol L2Bdenotes a rotational axis of a second arm 22B, the reference symbol L3Bdenotes a rotational axis of a third arm 23B, and the reference symbolL4B denotes a rotational axis of a gripping section 10B.

Here, it is assumed that the explanation will be presented exemplifyingthe first object W1 by a small-sized lightweight gear, and exemplifyingthe second object W2 by an electronic device provided with a supportshaft (a pin) for rotatably supporting the gear. It should be noted thatthe first object W1 has a roughly columnar shape having a curved surfaceon the side having contact with the gripping section.

As shown in FIG. 1, the robot 1 according to the present embodiment isprovided with the gripping sections 10A, 10B for gripping the object byopening and closing a pair of finger sections, the arms (moving device)20A, 20B for relatively moving the objects and the gripping sections10A, 10B, conveyer belts 33, 34 for conveying the first object W1, afeeder 36 for carrying the first object W1 on the first conveyer belt(moving device) 33, a stage 37 forming a pedestal used for transferringthe first object W1, a stage (moving device) 30 for mounting the objectsW1, W2, a base 50 for supporting the arms 20A, 20B and the stage 30,cameras 40A, 40B attached respectively to the arms 20A, 20B, a controldevice 60 for controlling the operation of the robot 1 itself, and aninput device 70 for performing instruction input to the control device60.

The gripping section 10A is coupled to a tip portion of the third arm23A. The gripping section 10A grips the first object W1 disposed on thefirst conveyer belt 33. The gripping section 10A conveys the firstobject W1 thus gripped to the stage 37. The gripping section 10A isprovided with a detection device 41A for detecting the force used forgripping the first object W1. As the detection device 41A, there can beused, for example, a pressure sensor, or a sensor for detecting thevariation in the torque of an electric motor (the variation in thecurrent flowing through the electric motor).

The gripping section 10B is coupled to a tip portion of the third arm23B. The gripping section 10B grips the first object W1 disposed on thestage 37. The gripping section 10B conveys the first object W1 thusgripped to the stage 30. The gripping section 10B conveys the firstobject W1 thus gripped (or disposed on the stage 37) to the secondobject W2. Specifically, the gripping section 10B inserts the pin of theelectronic device W2 into the gear W1. The gripping section 10B isprovided with a detection device 41B for detecting the force used forgripping the first object W1. As the detection device 41B, there can beused, for example, a pressure sensor, or a sensor for detecting thevariation in the torque of an electric motor (the variation in thecurrent flowing through the electric motor).

The arm 20A has the first arm 21A, the second arm 22A, and the third arm23A coupled in this order, and the first arm 21A is coupled to the base50 via a main shaft 24 having a rotational axis in the Z-axis directionand a bottom section 25 having a roughly rectangular planar shape. Thefirst arm 21A is disposed rotatably in forward and reverse directionsaround the rotational axis L1A in a horizontal direction (the directionparallel to the X-Y plane) at the joining section with the main shaft24. The second arm 22A is disposed rotatably in forward and reversedirections around the rotational axis L2A in the horizontal direction atthe joining section with the first arm 21A. The third arm 23A isdisposed rotatably in forward and reverse directions around therotational axis L3A in the horizontal direction and movably in up anddown directions (vertical directions (the Z-axis directions)) at thejoining section with the second arm 22A. It should be noted that thegripping section 10A is disposed rotatably in forward and reversedirections around the rotational axis L4A in a direction perpendicularto the horizontal direction at the joining section with the third arm23A.

The arm 20B has the first arm 21B, the second arm 22B, and the third arm23B coupled in this order, and the first arm 21B is coupled to the base50 via the main shaft 24 having the rotational axis in the Z-axisdirection and the bottom section 25 having a roughly rectangular planarshape. The first arm 21B is disposed rotatably in forward and reversedirections around the rotational axis L1B in the horizontal direction(the direction parallel to the X-Y plane) at the joining section withthe main shaft 24. The second arm 22B is disposed rotatably in forwardand reverse directions around the rotational axis L2B in the horizontaldirection at the joining section with the first arm 21B. The third arm23B is disposed rotatably in forward and reverse directions around therotational axis L3B in the horizontal direction and movably in up anddown directions (vertical directions (the Z-axis directions)) at thejoining section with the second arm 22B. It should be noted that thegripping section 10B is disposed rotatably in forward and reversedirections around the rotational axis L4B in a direction perpendicularto the horizontal direction at the joining section with the third arm23B.

The first conveyer belt 33 and the second conveyer belt 34 are disposeddistant from the side, on which the arm 20A is disposed, in this order.The feeder 36 is disposed on the upstream side (+Y-direction side) ofthe first conveyer belt 33. The second conveyer belt 34 is arranged tobe larger in size than the first conveyer belt 33 in a plan view so asto project toward the downstream direction (−Y-direction side) of thefirst conveyer belt 33. The first object W1 dropped from the firstconveyer belt 33 is conveyed by the second conveyer belt 34 and is thenthrown in an opening section 36 a of the feeder 36 by a tilted conveyerbelt not shown. It is arranged that the first object W1 having failed tobe gripped by the gripping section 10A is circulated through the firstconveyer belt 33, the second conveyer belt 34, and the feeder 36 in sucha manner as described above.

The stage 30 is provided with a top plate 31 for mounting the objects,and a base section 35 for supporting the top plate 31. The base section35 houses, for example, a moving mechanism for translating the top plate31 in the X-axis direction and a moving mechanism for moving the topplate 31 in the Y-axis direction independently from each other, and isdisposed so as to be able to move the top plate 31 in the horizontaldirections.

The camera 40A is attached to the tip portion of the second arm 22Aconstituting the arm 20A. As the camera 40A, for example, a CCD camerais used. The camera 40A takes the picture of the first object W1 mountedon the first conveyer belt 33. The shot image of the camera 40A istransmitted to the control device 60.

The camera 40B is attached to the tip portion of the second arm 22Bconstituting the arm 20B. As the camera 40B, for example, a CCD camerais used. The camera 40B takes the picture of the first object W1 and thesecond object W2 mounted on the top plate 31. The shot image of thecamera 40B is transmitted to the control device 60.

The control device 60 incorporates a memory, a CPU, a power supplycircuit, and so on. The control device 60 stores, for example, anoperation program for defining the operation content of the robot 1input from the input device 70, and starts up a variety of programsstored in the memory by the CPU to thereby perform the overall controlof the robot 1.

FIG. 2 is a plan view showing a configuration of the gripping sectionaccording to the first embodiment. In FIG. 2, the reference symbol P1denotes the distance between base ends of a pair of finger sections 12,the reference symbol P2 denotes the distance (the distance between theportions of the pair of finger sections furthest from each other)between bend sections of the pair of finger sections 12, the referencesymbol P3 denotes the distance between a main body section 11 and thebend sections of the pair of finger sections 12, and the referencesymbol P4 denotes the distance between the bend sections and tipportions of the pair of finger sections 12. Here, a configuration of thegripping section will be explained showing the gripping section 10A outof the gripping sections 10A, 10B as an example. Since the grippingsection 10B has substantially the same configuration as that of thegripping section 10A, the detailed explanation thereof will be omitted.

As shown in FIG. 2, the gripping section 10A is provided with the mainbody section 11 and the pair of finger sections 12. The main bodysection 11 has a roughly rectangular planar shape. The pair of fingersections 12 are coupled to one end of the main body section 11, and aredisposed movably based on the side (the side connected to the main bodysection 11) of the one end. Specifically, the gripping section 10A isarranged to translate the pair of finger sections 12 in a direction ofgetting away from each other and a direction of getting close to eachother to thereby open and close the pair of finger sections 12.

The “finger section” of the pair of finger sections 12 is composed ofone finger or a plurality of fingers. It should be noted that if thefinger section is composed of a plurality of fingers, the operation ofone of the fingers is followed by the operation of the rest of thefingers. In other words, it is not achievable that one of the fingersand the rest thereof operate independently from each other.

The moving mechanism (the slide mechanism) of the pair of fingersections 12 has, for example, a configuration of providing a lineargroove (through hole) to the main body section 11, providing aprojection to the base end of each of the pair of finger sections 12,and moving the pair of finger sections 12 along the linear groove by adrive device such as an electric motor. The pair of finger sections 12has a configuration of a “single-degree-of-freedom system (the system inwhich the position of an object can be expressed by a single parameter)”in which the two finger sections 12 are controlled using the distance ofthe translation as the single parameter.

The pair of finger sections 12 are formed bending so that the sidesopposed to each other each form a concave shape. The pair of fingersections 12 each have a plurality of (two) gripping surfaces 12 a, 12 bintersecting with each other on the side having contact with the firstobject W1 on the lateral side thereof. The pair of finger sections arearranged to have contact with the first object W1 at four or morecontact points in the gripping surfaces 12 a, 12 b for gripping thefirst object W1 from the lateral side thereof. By thus increasing thecontact points, it becomes easy to grip the first object W1 stably at apredetermined position. The pair of finger sections 12 can be formed by,for example, bending metal (flat plate) such as aluminum, or cutting themetal (rectangular solid).

In both of the pair of finger sections 12, the gripping surfaces 12 a,12 b (see FIG. 2) are perpendicular to the surface (the upper surface ofthe first conveyer belt 33) 33 a on which the first object W1 ismounted. It should be noted that in the explanation below, the surface(the upper surface of the first conveyer belt 33) on which the firstobject W1 is mounted is referred to simply as a “mounting surface” insome cases.

The distance P1 between the base ends of the pair of finger sections 12is set smaller than the distance P2 between the bend sections of thepair of finger sections 12. The distance P3 between the main bodysection 11 and the bend sections of the pair of finger sections 12 isset larger than the distance P4 between the bend sections and the tipsof the pair of finger sections 12. According to such a configuration, itresults that the first object W1 is gripped by the pair of fingersections 12 in the vicinity of the tips thereof. The control device 60performs the control so as to make the pair of finger sections 12 gripthe first object W1 at four or more contact points.

Incidentally, if the object is, for example, small-sized andlightweight, it becomes difficult to accurately detect the position andthe posture of the object using a camera, and accurate positioning ofthe gripping section for gripping the object is not achievable in somecases. If the accurate positioning of the gripping section is notachievable, the object and the gripping section might have contact witheach other at an unintended place during the gripping operation. On thatoccasion, since the object is lightweight, the object moves in anunintended direction, and there arises a problem that it is notachievable to hold the object at a desired position or a problem thatthe object flies out of the gripping space.

FIG. 16 is a diagram showing the relationship (the relationship betweenthe frictional force and the push-out force for realizing theself-alignment) between the forces generated when gripping an object WXwith a gripping section 10X. In FIG. 16, an X-Y coordinate system is seton the surface on which the object WX is disposed, and the contact pointbetween one side (−X-direction side) of the gripping section and theobject WX is set as an origin. In FIG. 16, the reference symbol Fdenotes the force with which the gripping section 10X pushes out theobject WX, the reference symbol f_(s) denotes the component of thepush-out force F in the direction of the incline of the gripping section10X, the reference symbol f_(y) denotes the X-axis direction componentof the push-out force F, the reference symbol f_(f) denotes thefrictional force exerted on the object WX from the gripping section 10X,and the reference symbol θ denotes the angle formed between the inclineof the gripping section 10X and the Y axis. It should be noted thatsince the mass of the object WX is small, the frictional force betweenthe object WX and the surface on which the object WX is disposed isignored in this drawing.

As shown in FIG. 16, by decomposing the force F with which the grippingsection 10X pushes out the object WX into the component f_(s) in thedirection of the incline of the gripping section 10X and the X-axisdirection component f_(y), the components are expressed as Formulas 1and 2 below. It should be noted that the component f_(y) is canceledout.

f _(s) =F tan θ  (1)

f _(y) =F/cos θ  (2)

Further, the frictional force f_(f) exerted on the object WX from thegripping section 10X can be expressed as Formula 3 below assuming thefrictional coefficient as μ.

f _(f) =μF  (3)

Here, the condition for the object WX to be pushed out by the grippingsection 10X is expressed as Formula 4 below.

f _(s) >f _(f)  (4)

Therefore, according to Formulas 1, 3, and 4, the condition for theobject WX to be pushed out by the gripping section 10X is expressed asFormula 5 below.

μ<tan θ  (5)

According to the above description, it is understood that when grippingthe object WX with the gripping section 10X, by fulfilling Formula 5, itis possible to push out the object WX with the gripping section 10X tothereby realize the self-alignment.

Therefore, the robot 1 according to the present embodiment of theinvention has a configuration provided with the gripping section 10A forgripping the object (the first object W1) by opening and closing thepair of finger sections 12, the moving device (the arm 20A, the firstconveyer belt 33) for moving the first object W1 and the grippingsection 10A relatively to each other, and the control device 60 forcontrolling the moving device to move the gripping section 10Arelatively toward the first object W1 to thereby dispose the pair offinger sections 12 in the vicinity of the first object W1, thencontrolling the gripping section 10A to open and close the pair offinger sections 12 in a plane parallel to the mounting surface 33 a onwhich the first object W1 is mounted to thereby pinch the first objectW1 between the pair of finger sections 12 from the lateral side of thefirst object W1, and thus making the gripping section 10A grip the firstobject W1 at three or more contact points. Hereinafter, the operation ofthe robot 1 according to the present embodiment will be explained withreference to FIGS. 3A through 3D, and 4.

FIGS. 3A through 3D are plan views showing the operation of the grippingsection according to the first embodiment. FIG. 4 is a flowchart showingthe operation of the robot 1 according to the first embodiment. FIG. 3Ashows the process of moving the gripping section 10A relatively towardthe first object W1, FIG. 3B shows the condition of disposing the pairof finger sections 12 in the periphery of the first object W1, FIG. 3Cshows the condition of pinching the first object W1 between the pair offinger sections 12 from the lateral side of the first object W1, andFIG. 3D shows the condition of making the gripping section 10A grip thefirst object W1. It should be noted that in FIGS. 3A through 3D thereference symbols G1, G2, G3, and G4 denote the contact points betweenthe pair of finger sections 12 and the first object W1. Here, theoperation of the gripping section will be explained showing the grippingsection 10A out of the gripping sections 10A, 10B as an example. Sincethe gripping section 10B has substantially the same configuration asthat of the gripping section 10A, the detailed explanation thereof willbe omitted.

Firstly, the first objects W1 are conveyed to the first conveyer belt 33using the feeder 36 (see FIG. 1). Subsequently, the image of the firstobject W1 is taken using the camera 40A. The control device 60 detectsthe position of the first object W1 mounted on the first conveyer belt33 (the mounting surface 33 a) based on the imaging result of the camera40A (step S1 shown in FIG. 4).

Subsequently, as shown in FIG. 3A, the control device 60 controls thearm 20A to move the gripping section 10A relatively toward the firstobject W1 (step S2 shown in FIG. 4). Subsequently, the control device 60controls the gripping section 10A to grip the first object W1 with thegripping section 10A. Here, the control device 60 makes the grippingsection 10A achieve the three functions, namely caging, self-alignment,and frictional gripping of the first object W1.

It should be noted that “caging” denotes the condition in which theobject (e.g., the first object W1) at a certain position and a postureexists in a space enclosed by the gripping section 10A and the plane(here, the upper surface 33 a of the first conveyer belt 33) on whichthe object is disposed. In the caging, the position and the posture ofthe first object W1 are not restricted, but remain free. The term“self-alignment” denotes the operation of moving the first object W1 toa predetermined position in the closed space due to the shape of thegripping section 10A and the frictional force between the grippingsection 10A and the first object W1 when pinching the first object W1with the gripping section 10A. The term “frictional gripping” denotesthe operation of making the gripping section 10A hold the first objectW1 by having contact therewith at three or more contact points, andholding the first object W1 in a direction perpendicular to the surface33 a on which the first object W1 is disposed using the frictionalforce, thereby gripping the first object W1.

Specifically, as shown in FIG. 3B, the pair of finger sections 12 isdisposed in the periphery of the first object W1, and then the grippingsection 10A is controlled to open and close the pair of finger sections12 in the plane parallel to the surface 33 a on which the first objectW1 is mounted to thereby make (step S3 shown in FIG. 4) the pair offinger sections 12 surround the periphery of the first object W1. Thus,the first object W1 is prevented from jumping out of the area surroundedby the pair of finger sections 12 (caging).

Subsequently, as shown in FIG. 3C, the first object W1 is pinchedbetween the pair of finger sections 12 from the lateral side of thefirst object W1 (step S4 shown in FIG. 4). Thus, the first object W1moves with the pair of finger sections 12, and thus the position thereofis adjusted (self-alignment).

Subsequently, as shown in FIG. 3D, the pair of finger sections 12 aremade (step S5 shown in FIG. 4) to grip the first object W1 at three ormore contact points (here, the four contact points G1, G2, G3, and G4).Thus, the first object W1 is held at a predetermined position(frictional gripping). On this occasion, the detection device (seeFIG. 1) provided to the gripping section 10A detects the force of thegripping section 10A for gripping the first object W1.

By setting the angle formed between the gripping surfaces 12 a, 12 b(see FIG. 2) and the mounting surface 33 a to the angle with which thelarge contact area with the first object W1 can be provided, it becomespossible to stably grip the first object W1 in the “frictionalgripping.”

Subsequently, the gripping section 10A conveys the first object W1 thusgripped to the stage 30 (see FIG. 1).

According to the robot 1 of the present embodiment, since the pair offinger sections 12 is opened and closed in a plane parallel to themounting surface 33 a after moving to the periphery of the first objectW1 due to the control of the control device 60, it results that theperiphery of the first object W1 is surrounded by the pair of fingersections 12. Thus, the first object W1 is prevented from jumping out ofthe area surrounded by the pair of finger sections 12 (caging). Further,since the pair of finger sections 12 pinch the first object W1 from thelateral side thereof, the first object W1 moves with the pair of fingersections 12, and thus the position is adjusted (self-alignment).Further, since the gripping section 10A grips the object at three ormore contact points (here, the four contact points G1, G2, G3, and G4),it is possible to restrict the position of the first object W1, and atthe same time, to stably grip the first object W1 due to the friction atthe contact points (frictional gripping). According to the operation ofthe gripping section 10A described above, the first object W1 can begripped at a predetermined position. Therefore, it is possible toprovide the robot 1 capable of preventing the first object W1 fromescaping, and reliably gripping the first object W1 at a predeterminedposition.

According to this configuration, since the gripping section 10Atranslates the pair of finger sections 12 in the direction of gettingaway from each other and the direction of getting close to each other tothereby open and close the pair of finger sections 12, it results thatthe pair of finger sections 12 are translated to each other to therebypinch the first object W1 from the lateral side. Therefore, it resultsthat the first object W1 moves in roughly the same direction as theopen/close direction of the pair of finger sections 12. Therefore, it ispossible to make the open/close mechanism of the pair of finger sections12 have an easy and simple configuration.

According to this configuration, the pair of finger sections 12 havecontact with the first object W1 at four or more contact points in thegripping surfaces 12 a, 12 b for gripping the first object W1 from thelateral side thereof. By thus increasing the contact points, it becomeseasy to grip the first object W1 stably at a predetermined position.

According to this configuration, since there is provided the camera 40Afor taking the picture of the first object W1, it is possible to performaccurate positioning of the gripping section 10A for gripping the firstobject W1.

According to this configuration, the gripping section 10A is providedwith the detection device 41A for detecting the force used for grippingthe first object W1. Therefore, the gripping force of the grippingsection 10A can be controlled so that no excessive load is applied tothe first object W1. Therefore, it becomes possible to prevent the firstobject W1 from being deformed or damaged when gripping the first objectW1.

It should be noted that although in the present embodiment, theexplanation is presented citing the example of providing two arms (thearm 20A and the arm 20B) to every robot, the number of arms is notlimited thereto. It is also possible to provide only one arm to everyrobot, or to provide three or more arms to every robot.

Further, although in the present embodiment, the explanation ispresented citing the case in which the first object has a roughlycolumnar shape as an example, the shape is not limited thereto. It isalso possible to use objects having a variety of shapes such as nuts orscrews besides the gears (gear wheels) as the first object.

Second Embodiment

FIG. 5 is a plan view corresponding to FIG. 2 and showing aconfiguration of a gripping section 110 according to a second embodimentof the invention. In FIG. 5, the reference symbol P11 denotes thedistance between the base ends in a pair of finger sections 112, thereference symbol P12 denotes the distance between the tips of the pairof finger sections 112. The gripping section 110 of the presentembodiment is different from the gripping section 10A explained in thefirst embodiment described above in the point that the first object W1is gripped at three or more contact points by making the first object W1have contact with the pair of finger sections 112 and the main bodysection 11. In FIG. 5, the elements substantially the same as thoseshown in FIG. 2 are denoted with the same reference symbols and thedetailed explanation therefor will be omitted.

As shown in FIG. 5, the gripping section 110 is provided with the mainbody section 11 and the pair of finger sections 112. The grippingsection 110 is arranged to translate the pair of finger sections 112 ina direction of getting away from each other and a direction of gettingclose to each other to thereby open and close the pair of fingersections 112.

The pair of finger sections 112 extend in one direction (here, theY-axis direction). The pair of finger sections 112 each have a flatgripping surface 112 a on the side having contact with the first objectW1 on the lateral side thereof. The gripping surface 112 a isperpendicular to the mounting surface 33 a. The control device 60 (seeFIG. 1) performs the control so as to make the pair of finger sections112 and the main body section 11 grip the first object W1 at three ormore contact points.

The distance P11 between the base ends of the pair of finger sections112 is set larger than the distance P12 between the tips of the pair offinger sections 112. According to such a configuration, it results thatthe first object W1 is gripped by the pair of finger sections 112 in thevicinity of the base ends thereof. Hereinafter, the operation of thegripping section 110 according to the present embodiment will beexplained with reference to FIGS. 4, and 6A through 6D.

FIGS. 6A through 6D are plan views corresponding respectively to FIGS.3A through 3D, and showing the operation of the gripping section 110according to the second embodiment. FIG. 6A shows the process of movingthe gripping section 110 relatively toward the first object W1, FIG. 6Bshows the condition of disposing the pair of finger sections 112 in theperiphery of the first object W1, FIG. 6C shows the condition ofpinching the first object W1 between the pair of finger sections 112from the lateral side of the first object W1, and FIG. 6D shows thecondition of making the gripping section 110 grip the first object W1.It should be noted that in FIGS. 6A through 6D the reference symbolsG11, G12, and G13 denote the contact points between the gripping section110 and the first object W1.

Regarding the step S1 shown in FIG. 4, since the operation issubstantially the same as the operation of the gripping section 10Aaccording to the first embodiment, the detailed explanation thereforwill be omitted.

As shown in FIG. 6A, the control device 60 controls the arm 20A (seeFIG. 1) to move the gripping section 110 relatively toward the firstobject W1 (step S2 shown in FIG. 4). Subsequently, the control device 60controls the gripping section 110 to grip the first object W1 with thegripping section 110. Here, the control device 60 makes the grippingsection 110 achieve the three functions, namely caging, self-alignment,and frictional gripping of the first object W1.

Specifically, as shown in FIG. 6B, the pair of finger sections 112 isdisposed in the periphery of the first object W1, and then the grippingsection 110 is controlled to open and close the pair of finger sections112 in the plane parallel to the mounting surface 33 a to thereby make(step S3 shown in FIG. 4) the pair of finger sections 112 surround theperiphery of the first object W1. Thus, the first object W1 is preventedfrom jumping out of the area surrounded by the pair of finger sections112 (caging).

Subsequently, as shown in FIG. 6C, the first object W1 is pinchedbetween the pair of finger sections 112 from the lateral side of thefirst object W1 (step S4 shown in FIG. 4). Thus, the first object W1moves with the pair of finger sections 112, and thus the positionthereof is adjusted (self-alignment).

Subsequently, as shown in FIG. 6D, the pair of finger sections 112 andthe main body section 11 are made (step S5 shown in FIG. 4) to grip thefirst object W1 at three or more contact points (here, the three contactpoints G11, G12, and G13). Thus, the first object W1 is held at apredetermined position (frictional gripping).

Third Embodiment

FIGS. 7A and 7B are diagrams showing a configuration of a grippingsection 210 according to the third embodiment of the invention. FIG. 7Ais a plan view corresponding to FIG. 2, and showing a configuration ofthe gripping section 210 according to the third embodiment of theinvention. FIG. 7B is a cross-sectional view showing a configuration ofthe gripping section 210 according to the third embodiment of theinvention. The gripping section 210 of the present embodiment isdifferent from the gripping section 10A explained in the firstembodiment described above in the point that a guard 212 c forpreventing the first object W1 from jumping out in a directionperpendicular to the mounting surface 33 a is disposed on the oppositeside of each of the pair of finger sections 212 to the mounting surface33 a across the first object W1. In FIGS. 7A and 7B, the elementssubstantially the same as those shown in FIG. 2 are denoted with thesame reference symbols and the detailed explanation therefor will beomitted.

As shown in FIGS. 7A and 7B, the gripping section 210 is provided withthe main body section 11 and the pair of finger sections 212. Thegripping section 210 is arranged to translate the pair of fingersections 212 in a direction of getting away from each other and adirection of getting close to each other to thereby open and close thepair of finger sections 212.

The pair of finger sections 212 each have a plurality of (two) grippingsurfaces 212 a, 212 b intersecting with each other on the side havingcontact with the first object W1 on the lateral side thereof. Thegripping surfaces 212 a, 212 b are perpendicular to the mounting surface33 a. The control device 60 (see FIG. 1) performs the control so as tomake the pair of finger sections 212 grip the first object W1 at four ormore contact points.

The guard 212 c for preventing the first object W1 from jumping out in adirection perpendicular to the mounting surface 33 a is disposed on theopposite side of each of the pair of finger sections 212 to the mountingsurface 33 a across the first object W1. The lower surface of the guard212 c is arranged to be parallel to the mounting surface 33 a.

FIGS. 8A and 8B are diagrams showing a condition of gripping the objectof the gripping section 210 according to the third embodiment of theinvention. FIG. 8A is a plan view corresponding to FIG. 7A, and showingthe condition of gripping the object of the gripping section 210according to the third embodiment of the invention. FIG. 8B is across-sectional view corresponding to FIG. 7B, and showing the conditionof gripping the object of the gripping section 210 according to thethird embodiment of the invention. It should be noted that in FIGS. 8Aand 8B the reference symbols G21, G22, G23, and G24 denote the contactpoints between the gripping section 210 and the first object W1.

As shown in FIG. 8A, the pair of finger sections 212 are controlled(step S5 shown in FIG. 4) to grip the first object W1 at four or morecontact points (here, the four contact points G21, G22, G23, and G24).Thus, the first object W1 is held at a predetermined position.

As shown in FIG. 8B, the bottom surface (−Z-direction side) of the firstobject W1 has contact with the mounting surface 33 a, and the topsurface (+Z-direction side) of the first object W1 has contact with thelower surface of the guard 212 c. In such a manner as described above,the first object W1 is gripped while having contact with the grippingsurfaces 212 a, 212 b, and the lower surface of the guard 212 c.

According to the robot of the present embodiment, it is possible toprevent the first object W1 from jumping out upward when pinching thefirst object W1.

It should be noted that although in the present embodiment, theexplanation is presented citing the configuration of providing theguards to both of the pair of finger sections as an example, theconfiguration is not limited thereto. It is also possible to adopt theconfiguration of, for example, providing the guard to either one of thepair of finger sections. In other words, it is sufficient for theconfiguration to provide the guard to at least one of the pair of fingersections. It should be noted that it is required for the guard to havethe area sufficient to prevent the first object from jumping out upward.

Fourth Embodiment

FIGS. 9A and 9B are diagrams showing a configuration of a grippingsection 310 according to a fourth embodiment of the invention. FIG. 9Ais a plan view corresponding to FIG. 7A, and showing a configuration ofthe gripping section 310 according to the fourth embodiment of theinvention. FIG. 9B is a side view showing the configuration of thegripping section 310 according to the fourth embodiment of theinvention. The gripping section 310 of the present embodiment isdifferent from the gripping section 210 explained in the thirdembodiment described above in the point that a pair of finger sections320 are each provided with a tip section 321 disposed in parallel to themounting surface 33 a and gripping the first object W1, and a base endsection 322 disposed in a direction getting apart from the mountingsurface 33 a and coupled to the main body section 11. In FIGS. 9A and9B, the elements substantially the same as those shown in FIGS. 7A and7B are denoted with the same reference symbols and the detailedexplanation therefor will be omitted.

As shown in FIGS. 9A and 9B, the gripping section 310 is provided withthe main body section 11 and the pair of finger sections 320. Thegripping section 310 is arranged to translate the pair of fingersections 320 in a direction of getting away from each other and adirection of getting close to each other to thereby open and close thepair of finger sections 320.

The pair of finger sections 320 are each provided with the tip section321 disposed in parallel to the mounting surface 33 a and gripping thefirst object W1, and the base end section 322 disposed in the directiongetting apart from the mounting surface 33 a and coupled to the mainbody section 11.

The tip section 321 of each of the pair of finger sections 320 has aplurality of gripping surfaces (here, the two surfaces) 321 a, 321 bintersecting with each other on the side having contact with the firstobject W1 on the lateral side thereof. The gripping surfaces 321 a, 321b are perpendicular to the mounting surface 33 a. The control device 60(see FIG. 1) performs the control so as to make the tip sections 321 ofthe pair of finger sections 320 grip the first object W1 at four or morecontact points.

The guard 321 c for preventing the first object W1 from jumping out in adirection perpendicular to the mounting surface 33 a is disposed on theopposite side of the tip section 321 of each of the pair of fingersections 320 to the mounting surface 33 a across the first object W1.

The surface 321 d of the tip section 321 of each of the pair of fingersections 320 opposed to the mounting surface 33 a is a flat plane.

In the pair of finger sections 320, the tip section 321 and the base endsection 322 are arranged so as not to overlap each other viewed from thedirection (here, the Z-axis direction) in which the image of the tipsection 321 is taken by the camera 340. It should be noted that thecamera 340 is disposed at the position overlapping the first object W1viewed from the direction perpendicular to the mounting surface 33 a.

In the pair of finger sections 320, the angle θ1 formed between the tipsection 321 and the base end section 322 is an obtuse angle.

According to the robot of the present embodiment, it becomes easy togrip the first object W1 at a predetermined position compared to theconfiguration in which whole of the pair of finger sections is disposedin parallel to the mounting surface. In the case of gripping the firstobject mounted on the mounting surface, by making the pair of fingersections perform the gripping operation while making the pair of fingersections have contact with the mounting surface, it becomes easy tostably grip the first object. If there is adopted the configuration, forexample, in which the tip section and the base end section are arrangedin parallel to each other in the pair of finger sections, the main bodysection and the mounting surface have contact with each other whengripping the first object, and the tip section and the mounting surfacebecome distant from each other to thereby make it difficult to grip thefirst object. However, according to the configuration of the presentembodiment of the invention, it becomes easy to make the tip sections321 of the pair of finger sections 320 have contact with the mountingsurface 33 a. Therefore, it becomes easy to grip the first object W1 ata predetermined position.

According to this configuration, it becomes easy to make the tipsections 321 of the pair of finger sections 320 have contact with themounting surface 33 a compared to the configuration in which the surfaceof the tip section of each of the pair of finger sections opposed to themounting surface is an uneven surface. Therefore, it becomes easy togrip the first object W1 at a predetermined position.

According to this configuration, it is possible to perform the grippingoperation while checking the gripping operation of the tip sections 321.

According to this configuration, it becomes easy to perform the grippingoperation while checking the gripping operation of the tip sections 321compared to the configuration in which the angle formed between the tipsection and the base end section is an acute angle. If there is adopteda configuration, for example, in which the angle formed between the tipsection and the base end section is an acute angle, there is apossibility that the tip section is shaded by the base end section whenviewed from the direction in which the image of the tip section is takenby the camera, and it becomes difficult to detect the accurate grippingoperation of the tip sections. However, according to the configurationof the present embodiment of the invention, the tip sections 321 arehardly shaded by the base end sections 322 viewed from the direction inwhich the image of the tip sections 321 is taken by the camera 340.Therefore, it becomes easy to perform the gripping operation whilechecking the gripping operation of the tip sections 321.

Fifth Embodiment

FIG. 10 is a plan view corresponding to FIG. 2 and showing aconfiguration of a gripping section 410 according to a fifth embodimentof the invention. In FIG. 10, the reference symbol P21 denotes thedistance between base ends of a pair of finger sections, the referencesymbol P22 denotes the distance between bend sections of the pair offinger sections, the reference symbol P23 denotes the distance between amain body section and the bend sections of the pair of finger sections,and the reference symbol P24 denotes the distance between the bendsections and tip portions of the pair of finger sections. Further, thereference symbol θ2 denotes the angle (specifically, the angle formedbetween sections each forming a surface 412 b in a pair of fingersections 412) formed between the pair of finger sections 412. A grippingsection 410 of the present embodiment is different from the grippingsection 10A explained in the first embodiment described above in thepoint that the pair of finger sections 412 is opened and closed byrotating the pair of finger sections 412 around respective rotatingshafts (rotational axes) 413 perpendicular to the mounting surface 33 a.In FIG. 10, the elements substantially the same as those shown in FIG. 2are denoted with the same reference symbols and the detailed explanationtherefor will be omitted.

As shown in FIG. 10, the gripping section 410 is provided with the mainbody section 411 and the pair of finger sections 412. The pair of fingersections 412 are coupled to one end of the main body section 411, andare disposed movably based on the side (the side connected to the mainbody section 411) of the one end. Specifically, the gripping section 410is arranged to open and close the pair of finger sections 412 byrotating the pair of finger sections 412 around the respective rotatingshafts 413 perpendicular to the mounting surface 33 a.

The moving mechanism (the rotating mechanism) of the pair of fingersections 412 has a configuration of, for example, providing recesses(through holes) to the main body section 411, providing the rotatingshafts 413 to the base ends of the pair of finger sections 412, androtatably disposing the rotating shafts 413 in the respective recessesto thereby rotate the pair of finger sections 412 around the respectiverotating shafts 413 by a drive device such as an electric motor. Thepair of finger sections 412 has a configuration of a“single-degree-of-freedom system (the system in which the position of anobject can be expressed by a single parameter)” in which the two fingersections 412 are controlled using the rotational angle of the rotationof each of the two finger sections 412 around the rotating shaft 413 asthe single parameter.

The pair of finger sections 412 each have a plurality of grippingsurfaces 412 a, 412 b intersecting with each other on the side havingcontact with the first object W1 on the lateral side thereof. Thegripping surfaces 412 a, 412 b are perpendicular to the mounting surface33 a. The control device 60 (see FIG. 1) performs the control so as tomake the pair of finger sections 412 grip the first object W1 at four ormore contact points.

FIGS. 11A through 11D are plan views corresponding respectively to FIGS.3A through 3D, and showing the operation of the gripping section 410according to the fifth embodiment.

FIG. 11A shows the process of moving the gripping section 410 relativelytoward the first object W1, FIG. 11B shows the condition of disposingthe pair of finger sections 412 in the periphery of the first object W1,FIG. 11C shows the condition of pinching the first object W1 between thepair of finger sections 412 from the lateral side of the first objectW1, and FIG. 11D shows the condition of making the gripping section 410grip the first object W1. It should be noted that in FIGS. 11A through11D the reference symbols G31, G32, G33, and G34 denote the contactpoints between the pair of fingers 412 and the first object W1.

Regarding the step S1 shown in FIG. 4, since the operation issubstantially the same as the operation of the gripping section 10Aaccording to the first embodiment, the detailed explanation thereforwill be omitted.

As shown in FIG. 11A, the control device 60 controls the arm 20A (seeFIG. 1) to move the gripping section 410 relatively toward the firstobject W1 (step S2 shown in FIG. 4). The angle formed between the pairof finger sections on this occasion is assumed as θ2 a. Subsequently,the control device 60 controls the gripping section 410 to grip thefirst object W1 with the gripping section 410. Here, the control device60 makes the gripping section 410 achieve the three functions, namelycaging, self-alignment, and frictional gripping of the first object W1.

Specifically, as shown in FIG. 11B, the pair of finger sections 412 isdisposed in the periphery of the first object W1, and then the grippingsection 410 is controlled to open and close the pair of finger sections412 in the plane parallel to the mounting surface 33 a to thereby make(step S3 shown in FIG. 4) the pair of finger sections 412 surround theperiphery of the first object W1. Thus, the first object W1 is preventedfrom jumping out of the area surrounded by the pair of finger sections412 (caging). It should be noted that the angle θ2 b formed between thepair of finger sections 412 on this occasion is set smaller than theangle θ2 a (θ2 b<θ2 a).

Subsequently, as shown in FIG. 11C, the first object W1 is pinchedbetween the pair of finger sections 412 from the lateral side of thefirst object W1 (step S4 shown in FIG. 4). Thus, the first object W1moves with the pair of finger sections 412, and thus the positionthereof is adjusted (self-alignment). It should be noted that the angleθ2 c formed between the pair of finger sections 412 on this occasion isset smaller than the angle θ2 b (θ2 c<θ2 b).

Then, as shown in FIG. 11D, the pair of finger sections 412 are made(step S5 shown in FIG. 4) to grip the first object W1 at three or morecontact points (here, the four contact points G31, G32, G33, and G34).Thus, the first object W1 is held at a predetermined position(frictional gripping). It should be noted that the angle θ2 d formedbetween the pair of finger sections 412 on this occasion is set smallerthan the angle θ2 c (θ2 d<θ2 c).

According to the robot of the present embodiment, it is arranged thatthe pair of finger sections 412 rotate to thereby pinch the first objectW1 from the lateral side thereof. Therefore, it results that the firstobject W1 moves so as to be pulled in in the direction of the rotationof the pair of finger sections 412. Therefore, it is possible to makethe open/close mechanism of the pair of finger sections 412 have an easyand simple configuration.

First Modified Example

FIGS. 12A through 12C are plan views corresponding to FIG. 2, andshowing first through third modified examples of the gripping sectionaccording to the invention. FIG. 12A is a plan view showing the firstmodified example of the gripping section according to the invention. Itshould be noted that in FIGS. 12A through 12C, the first object W1 isomitted from the illustration for the sake of convenience. A grippingsection 501 of the present modified example is different from thegripping section 10A explained in the first embodiment described abovein the point that a pair of finger sections 512 each have a curvedsurface 512 b on the side having contact with the first object W1 on thelateral side thereof. In FIG. 12A, the elements substantially the sameas those shown in FIG. 2 are denoted with the same reference symbols andthe detailed explanation therefor will be omitted.

As shown in FIG. 12A, the gripping section 501 of the present modifiedexample is provided with a main body section 511 and the pair of fingersections 512. The gripping section 501 is arranged to translate the pairof finger sections 512 in a direction of getting away from each otherand a direction of getting close to each other to thereby open and closethe pair of finger sections 512.

The pair of finger sections 512 each have a plurality of grippingsurfaces 512 a, 512 b intersecting with each other on the side havingcontact with the first object W1 on the lateral side thereof. Thegripping surfaces 512 a, 512 b are perpendicular to the mounting surface33 a. The control device 60 (see FIG. 1) performs the control so as tomake the pair of finger sections 512 grip the first object W1 at four ormore contact points.

The pair of finger sections 512 each have the curved surface 512 b onthe side having contact with the first object W1 on the lateral sidethereof. Specifically, the gripping surface 512 b located closer to themain body section 511 out of the plurality of surfaces 512 a, 512 b isformed as a curved surface convex toward the side having contact withthe first object W1 on the lateral side thereof.

Second Modified Example

FIG. 12B is a plan view corresponding to FIG. 10, and showing the secondmodified example of the gripping section according to the invention. Agripping section 502 of the present modified example is different fromthe gripping section 410 explained in the fifth embodiment describedabove in the point that a pair of finger sections 522 each have a curvedsurface 522 b on the side having contact with the first object W1 on thelateral side thereof. In FIG. 12B, the elements substantially the sameas those shown in FIG. 10 are denoted with the same reference symbolsand the detailed explanation therefor will be omitted.

As shown in FIG. 12B, the gripping section 502 is provided with a mainbody section 521 and the pair of finger sections 522. The grippingsection 502 is arranged to open and close the pair of finger sections522 by rotating the pair of finger sections 522 around respectiverotating shafts 523 perpendicular to the mounting surface 33 a.

The pair of finger sections 522 each have a plurality of grippingsurfaces 522 a, 522 b intersecting with each other on the side havingcontact with the first object W1 on the lateral side thereof. Thegripping surfaces 522 a, 522 b are perpendicular to the mounting surface33 a. The control device 60 (see FIG. 1) performs the control so as tomake the pair of finger sections 522 grip the first object W1 at four ormore contact points.

The pair of finger sections 522 each have the curved surface 522 b onthe side having contact with the first object W1 on the lateral sidethereof. Specifically, the gripping surface 522 b located closer to themain body section 521 out of the plurality of surfaces 522 a, 522 b isformed as a curved surface convex toward the side having contact withthe first object W1 on the lateral side thereof.

Third Modified Example

FIG. 12C is a plan view corresponding to FIG. 10, and showing the thirdmodified example of the gripping section according to the invention. Agripping section 503 is different from the gripping section 410explained in the fifth embodiment described above in the point that apair of finger sections 532 extend in one direction. In FIG. 12C, theelements substantially the same as those shown in FIG. 10 are denotedwith the same reference symbols and the detailed explanation thereforwill be omitted.

As shown in FIG. 12C, the gripping section 503 is provided with a mainbody section 531 and the pair of finger sections 532. The grippingsection 503 is arranged to open and close the pair of finger sections532 by rotating the pair of finger sections 532 around respectiverotating shafts 533 perpendicular to the mounting surface 33 a.

The pair of finger sections 532 extend in one direction (here, theY-axis direction). The pair of finger sections 532 each have a flatgripping surface 532 a on the side having contact with the first objectW1 on the lateral side thereof. The gripping surface 532 a isperpendicular to the mounting surface 33 a. The control device 60 (seeFIG. 1) performs the control so as to make the pair of finger sections532 and the main body section 531 grip the first object W1 at three ormore contact points.

Fourth Modified Example

FIGS. 13A through 13F are plan views corresponding to FIG. 2, andshowing fourth through ninth modified examples of the gripping sectionaccording to the invention. FIG. 13A is a plan view showing the fourthmodified example of the gripping section according to the invention. Itshould be noted that in FIGS. 13A through 13F, the first object W1 isomitted from the illustration, and the pair of finger sections arerepresented by lines for the sake of convenience. Further, theconfigurations described as the fourth through ninth modified examplescan be applied to both of the configuration in which the pair of fingersections are translated and the configuration in which the pair offinger sections move rotationally.

As shown in FIG. 13A, a gripping section 601 of the present modifiedexample is provided with a main body section 611 and a pair of fingersections 612. The pair of finger sections 612 are coupled to one end ofthe main body section 611, and are disposed movably based on the side(the side connected to the main body section 611) of the one end.

The pair of finger sections 612 each have a gripping surface 612 a onthe side having contact with the first object W1 on the lateral sidethereof. The gripping surface 612 a is formed as a curved surfaceconcave toward the side having contact with the first object W1 on thelateral side thereof. The gripping surface 612 a is perpendicular to themounting surface 33 a. The control device 60 (see FIG. 1) performs thecontrol so as to make the pair of finger sections 612 grip the firstobject W1 at four or more contact points.

Fifth Modified Example

FIG. 13B is a plan view showing the fifth modified example of thegripping section according to the invention. As shown in FIG. 13B, agripping section 602 of the present modified example is provided with amain body section 621 and a pair of finger sections 622. The pair offinger sections 622 are coupled to one end of the main body section 621,and are disposed movably based on the side (the side connected to themain body section 621) of the one end.

The pair of finger sections 622 each have a plurality of grippingsurfaces 622 a, 622 b intersecting with each other on the side havingcontact with the first object W1 on the lateral side thereof. Thegripping surfaces 622 a, 622 b are each formed as a curved surfaceconvex toward the side having contact with the first object W1 on thelateral side thereof. The gripping surfaces 622 a, 622 b areperpendicular to the mounting surface 33 a. The control device 60 (seeFIG. 1) performs the control so as to make the pair of finger sections622 grip the first object W1 at four or more contact points.

Sixth Modified Example

FIG. 13C is a plan view showing the sixth modified example of thegripping section according to the invention. As shown in FIG. 13C, agripping section 603 of the present modified example is provided with amain body section 631 and a pair of finger sections 632A, 632B. The pairof finger sections 632A, 632B are coupled to one end of the main bodysection 631, and are disposed movably based on the side (the sideconnected to the main body section 631) of the one end.

The finger section 632A, one of the pair of finger sections 632A, 632B,has a flat gripping surface 632Aa on the side having contact with thefirst object W1 on the lateral side thereof. The gripping surface 632Aais perpendicular to the mounting surface 33 a.

The finger section 632B, the other of the pair of finger sections 632A,632B, has a gripping surface 632Ba on the side having contact with thefirst object W1 on the lateral side thereof. The gripping surface 632Bais formed as a curved surface concave toward the side having contactwith the first object W1 on the lateral side thereof. The grippingsurface 632Ba is perpendicular to the mounting surface 33 a. The controldevice 60 (see FIG. 1) performs the control so as to make the pair offinger sections 632A, 632B grip the first object W1 at three or morecontact points.

Seventh Modified Example

FIG. 13D is a plan view showing the seventh modified example of thegripping section according to the invention. As shown in FIG. 13D, agripping section 604 of the present modified example is provided with amain body section 641 and a pair of finger sections 642A, 642B. The pairof finger sections 642A, 642B are coupled to one end of the main bodysection 641, and are disposed movably based on the side (the sideconnected to the main body section 641) of the one end.

The finger section 642A, one of the pair of finger sections 642A, 642B,has a flat gripping surface 642Aa on the side having contact with thefirst object W1 on the lateral side thereof. The gripping surface 642Aais perpendicular to the mounting surface 33 a.

The finger section 642B, the other of the pair of finger sections 642A,642B, has a plurality of gripping surfaces 642Ba, 642Bb intersectingwith each other on the side having contact with the first object W1 onthe lateral side thereof. The gripping surfaces 642Ba, 642Bb are eachformed as a curved surface convex toward the side having contact withthe first object W1 on the lateral side thereof. The gripping surfaces642Ba, 642Bb are perpendicular to the mounting surface 33 a. The controldevice 60 (see FIG. 1) performs the control so as to make the pair offinger sections 642A, 642B grip the first object W1 at three or morecontact points.

Eighth Modified Example

FIG. 13E is a plan view showing the eighth modified example of thegripping section according to the invention. As shown in FIG. 13E, agripping section 605 of the present modified example is provided with amain body section 651 and a pair of finger sections 652. The pair offinger sections 652 are coupled to one end of the main body section 651,and are disposed movably based on the side (the side connected to themain body section 651) of the one end.

The pair of finger sections 652 each have a plurality of flat surfaces652 a, 652 b, and 652 c intersecting with each other on the side havingcontact with the first object W1 on the lateral side thereof. Thesurfaces 652 a, 652 b, and 652 c are continuously adjacent to eachother. The surfaces 652 a, 652 b out of the surfaces 652 a, 652 b, and652 c form gripping surfaces for gripping the first object W1. Incontrast, the surface 652 c, the rest of the surfaces, forms a surfacenot gripping the first object W1. The surfaces 652 a, 652 b, and 652 care perpendicular to the mounting surface 33 a. The control device 60(see FIG. 1) performs the control so as to make the pair of fingersections 652 (the surfaces 652 a, 652 b) grip the first object W1 atfour or more contact points.

Ninth Modified Example

FIG. 13F is a plan view showing the ninth modified example of thegripping section according to the invention. As shown in FIG. 13F, agripping section 606 of the present modified example is provided with amain body section 661 and a pair of finger sections 662. The pair offinger sections 662 are coupled to one end of the main body section 661,and are disposed movably based on the side (the side connected to themain body section 661) of the one end.

The pair of finger sections 662 each have a plurality of flat surfaces662 a, 662 b, and 662 c intersecting with each other on the side havingcontact with the first object W1 on the lateral side thereof. Thesurfaces 662 a, 662 b out of the surfaces 662 a, 662 b, and 662 c arecontinuously adjacent to each other. The surfaces 662 a, 662 b out ofthe surfaces 662 a, 662 b, and 662 c form gripping surfaces for grippingthe first object W1. In contrast, the surface 662 c, the rest of thesurfaces, forms a surface not gripping the first object W1. The surfaces662 a, 662 b, and 662 c are perpendicular to the mounting surface 33 a.The control device 60 (see FIG. 1) performs the control so as to makethe pair of finger sections 662 (the surfaces 662 a, 662 b) grip thefirst object W1 at four or more contact points.

Tenth Modified Example

FIG. 14 is a plan view corresponding to FIG. 2, and showing the tenthmodified example of the gripping section according to the invention. Itshould be noted that the configuration described as the tenth modifiedexample can be applied to both of the configuration in which the pair offinger sections are translated and the configuration in which the pairof finger sections move rotationally.

As shown in FIG. 14, a gripping section 607 of the present modifiedexample is provided with a main body section 671 and a pair of fingersections 672A, 672B. The pair of finger sections 672A, 672B are coupledto one end of the main body section 671, and are disposed movably basedon the side (the side connected to the main body section 671) of the oneend.

The finger section 672A, one of the pair of finger sections 672A, 672B,is formed having a concave shape on the side having contact with thefirst object W1 on the lateral side thereof. The finger section 672A,the one of the pair of finger sections 672A, 672B, has a plurality offlat surfaces 672Aa, 672Ab intersecting with each other on the sidehaving contact with the first object W1 on the lateral side thereof. Thesurfaces 672Aa, 672Ab are continuously adjacent to each other. Thesurfaces 672Aa, 672Ab form gripping surfaces for gripping the firstobject W1. The surfaces 672Aa, 672Ab are perpendicular to the mountingsurface 33 a.

The finger section 672B, the other of the pair of finger sections 672A,672B, is formed having a convex shape on the side having contact withthe first object W1 on the lateral side thereof. The finger section672B, the other of the pair of finger sections 672A, 672B, has aplurality of flat surfaces 672Ba, 672Bb intersecting with each other onthe side having contact with the first object W1 on the lateral sidethereof. The surfaces 672Ba, 672Bb are continuously adjacent to eachother. The part (bend section) where the surfaces 672Ba, 672Bb intersectwith each other forms the part for gripping the first object W1. Thesurfaces 672Ba, 672Bb are perpendicular to the mounting surface 33 a.The control device 60 (see FIG. 1) performs the control so as to makethe pair of finger sections 672A, 672B (the surfaces 672Aa, 672Ab of theone finger section 672A, and the bend section of the other fingersection 672B) grip the first object W1 at three or more contact points.

Eleventh Modified Example

FIGS. 15A through 15C are side views corresponding to FIG. 9B, andshowing eleventh through thirteenth modified examples of the grippingsection according to the invention. FIG. 15A is a side view showing theeleventh modified example of the gripping section according to theinvention. It should be noted that, the configurations described as theeleventh through thirteenth modified examples can be applied to both ofthe configuration in which the pair of finger sections are translatedand the configuration in which the pair of finger sections moverotationally.

As shown in FIG. 15A, a gripping section 701 of the present modifiedexample is provided with a main body section 711 and a pair of fingersections 720. The pair of finger sections 720 are coupled to one end ofthe main body section 711, and are disposed movably based on the side(the side connected to the main body section 711) of the one end.

The pair of finger sections 720 are each provided with a tip section 721disposed in parallel to the mounting surface 33 a and gripping the firstobject W1, and a base end section 722 disposed in the direction gettingapart from the mounting surface 33 a and coupled to the main bodysection 711.

In the pair of finger sections 720, the tip section 721 and the base endsection 722 are arranged so as not to overlap each other viewed from thedirection in which the image of the tip section 721 is taken by a camera740. In the pair of finger sections 720, the angle θ3 formed between thetip section 721 and the base end section 722 is an obtuse angle. Thecamera 740 is attached to the main body section 711.

According to the robot of the present modified example, since the camera740 is disposed at a position near to the pair of finger sections 720,it is possible to perform accurate positioning of the pair of fingersections 720 for gripping the first object W1.

Twelfth Modified Example

FIG. 15B is a side view showing the twelfth modified example of thegripping section according to the invention. It should be noted that inFIG. 15B, the first object W1 is omitted from the illustration for thesake of convenience.

As shown in FIG. 15B, a gripping section 702 of the present modifiedexample is provided with the main body section 711 and a pair of fingersections 720A. The pair of finger sections 720A are coupled to one endof the main body section 711, and are disposed movably based on the side(the side connected to the main body section 711) of the one end.

The pair of finger sections 720A are each provided with a tip section721A disposed in parallel to the mounting surface 33 a and gripping thefirst object W1, and a base end section 722A disposed in the directiongetting apart from the mounting surface 33 a and coupled to the mainbody section 711. A connection section between the tip section 721A andthe base end section 722A has a curved shape.

In the pair of finger sections 720A, the tip section 721A and the baseend section 722A are arranged so as not to overlap each other viewedfrom the direction in which the image of the tip section 721A is takenby the camera 740. In the pair of finger sections 720A, the angle (theangle formed between the straight portions in a side view) θ4 formedbetween the tip section 721A and the base end section 722A is an obtuseangle. The camera 740 is attached to the main body section 711.

Thirteenth Modified Example

FIG. 15C is a side view showing the thirteenth modified example of thegripping section according to the invention. It should be noted that inFIG. 15C, the first object W1 is omitted from the illustration for thesake of convenience.

As shown in FIG. 15C, a gripping section 703 of the present modifiedexample is provided with the main body section 711 and a pair of fingersections 720B. The pair of finger sections 720B are coupled to one endof the main body section 711, and are disposed movably based on the side(the side connected to the main body section 711) of the one end.

The pair of finger sections 720B are each provided with a tip section721B disposed in parallel to the mounting surface 33 a and gripping thefirst object W1, and a base end section 722B disposed in the directiongetting apart from the mounting surface 33 a and coupled to the mainbody section 711.

In the pair of finger sections 720B, the tip section 721B and the baseend section 722B are arranged so as not to overlap each other viewedfrom the direction in which the image of the tip section 721B is takenby the camera 740. In the pair of finger sections 720B, the angle (theangle formed between the straight portions in a side view) formedbetween the tip section 721B and the base end section 722B is a rightangle. The camera 740 is attached to the main body section 711.

It should be noted that although in the embodiments described above therobot has the configuration of moving the gripping section using ascalar robot, and making the gripping section grip the object, theconfiguration is not limited thereto. It is also possible to adopt aconfiguration of, for example, moving the gripping section using a robotof another type such as a Cartesian coordinate robot, and making thegripping section grip the object.

Further, although in the embodiments described above the robot has theconfiguration in which the arms (the moving devices) are attached on thebase, the configuration is not limited thereto. It is also possible toadopt a configuration in which a bridge section striding the stage isattached to the base, and the arms are suspended from the bridgesection.

The entire disclosure of Japanese Patent Application No. 2010-206661,filed Sep. 15, 2010 and No. 2010-260627, filed Nov. 22, 2010 areexpressly incorporated by reference herein.

What is claimed is:
 1. A robot comprising: a gripping section adapted togrip an object by open and close a pair of finger sections; a movingdevice adapted to relatively move the object and the gripping section;and a control device adapted to control the moving device to move thegripping section relatively toward the object, and dispose the pair offinger sections in a periphery of the object, and then control thegripping section to open and close the pair of finger sections in aplane parallel to a mounting surface on which the object is mounted,pinch the object between the pair of finger sections from a lateral sideof the object, and grip the object with the gripping section at leastthree contact points.
 2. The robot according to claim 1 wherein thegripping section opens and closes the pair of finger sections bytranslating the pair of finger sections in a direction of getting awayfrom each other and a direction of getting close to each other.
 3. Therobot according to claim 1 wherein the gripping section opens and closesthe pair of finger sections by rotating at least one of the pair offinger sections around a rotational axis perpendicular to the mountingsurface.
 4. The robot according to claim 1 wherein at least one of thepair of finger sections has contact with the object at least two contactpoints on a gripping surface adapted to grip the object from the lateralside.
 5. The robot according to claim 1 wherein the gripping section isprovided with a main body section to which the pair of finger sectionsare coupled, and grips the object at least three contact points bymaking the object have contact with the pair of finger sections and themain body section.
 6. The robot according to claim 1 wherein at leastone of the pair of finger sections has a guard adapted to prevent theobject from jumping out in a direction perpendicular to the mountingsurface, the guard being disposed on an opposite side to the mountingsurface across the object.
 7. The robot according to claim 1 furthercomprising: a camera adapted to take a picture of the object, whereinthe control device detects a position of the object based on a result oftaking a picture by the camera, and then controls the moving device tomove the gripping section relatively toward the object.
 8. The robotaccording to claim 7 wherein the gripping section is provided with amain body section to which the pair of finger sections are coupled, andthe camera is attached to the main body section.
 9. The robot accordingto claim 7 wherein each of the pair of finger sections includes a tipsection disposed in parallel to the mounting surface, and adapted togrip the object, and a base end section disposed in a direction ofgetting apart from the mounting surface, and coupled to the main bodysection.
 10. The robot according to claim 9 wherein the tip section ofeach of the pair of finger sections has a flat surface opposed to themounting surface.
 11. The robot according to claim 9 wherein the tipsection and the base end section are arranged so as to eliminate anoverlap between the tip section and the base end section in a view froma direction in which the camera takes a picture of the tip section. 12.The robot according to claim 9 wherein an angle formed between the tipsection and the base end section is an obtuse angle.
 13. The robotaccording to claim 1 wherein the gripping section includes a detectiondevice adapted to detect a force for gripping the object, and thecontrol device controls the force of the gripping section for grippingthe object based on a detection result of the detection device.